Lubricating seal



July 27, 1943. J. s. swr-:ARINGEN LUBRI CAT ING SEAL Filed Jan. 30, 19392 Sheets-SheetI 1 July'27, 1943- J. s. swEARlNGEN 2,325,283 nLUBRICATING SEAL Filed Jan. 30, 1939 2 Sheets-Shea?l 2 Patented July 27,1943 UNITDSTTS PAT ,2,325,283- LUBRICATING SEAL Judson S. Swcaringen,SanAntonio, Tex.

Application'Januaryfso, 1939, I serial No. 253,693

reclaim. (o1. 30sg-'saar f This invention relates to the-art of lfluidcompressors of the high speed. centrifugal type, such as 4commonly.employ multi-stage compression, wherein the uid impellermeans iscarried .-.by

a driven shaft which projects vthrough theendwalls of thecompressorcasing and passes through Y' wall means separating 5 thevariousustages.; In order to prevent pressure loss by leakage offthefluid being.. compressed axially back along. the

shaft from high to lowV pressure points, theshaft beaings'must besealedagainst suchpassage vof fluid. Y

At relativelylow speeds ashaftpacking or' stuffing boxl seal is':generally sufcient,. using` either' @dry lubricant, a Viscouslubricant, or :a:` very-thin'lm of' somelirnpid lubricant." At highspeeds, however, such as 3,000'to *10;000. Rf. P.1M...

and higher, they resultant paucity of 'lubrication and small clearancebetweenshaft and packing;

combinedA withhigh pressures cause rapid Wear and heat generation whichare immediatelyvree. .f

ectedin powerjloss and in. bearing damage.

These factors .imposey definite limits of. operatngf:

speeds and output, even-.Whenexte'rnal cooling'I systems areemployed forwell; designed and' ader-uA quately lubricated Vbearings when. thelspeed is Ylit follows, therefora;

that in -zorder to .'obtain; maximum efficiency at high speeds theremust exist avery denite`-1adial clearance between the shaft surface;and, its bearing,;with no vdirect contact between shaft'and bearing, and',wi th a full f film off Ilubricant separating; the moving parts,4filling the: space therebetweenA and providing the y; entire support forthe shaft; In such anorgani-.y

zation the lubricant Imseals the shaft; against leakage of thecompressor fluid either between the stages or at the v casing, e.1ids..'pTothisend the lubricant mustbe vplaced under such *pres-f sure thatit willtend toiiowthrough the bearing.'

toward the high pressure side thereof.

It is an object of Ythis invention to provide., a means for imposingsuch a pressure upon thelubricant that it will nou/,through the bea-ringtoward'thehigh pressureside thereof, without employing a structure suchas the ordinary stuff` ing boit whichl would become inoperative under ithe k high speeds this invention.

It is a further object to provide such a means-y and 'pressurescontemplated by.y A

in which theeffect of normal endA` play inthe shaft of a machine of thistype will bemini mized to such an extent that it will not interferesealing means.Y Y

with the proper operation of the rbearingand` 'and arrangement of parts.

linee-e3v of Figure 2*.v

Accordingly, an cbjecto-f thepreserltinlentln. is to pro-vide. astructure-Which maybe used .in f a high speed centrifugalfiuid.-con'ipressor or, other comparablev situation, whichstructurewillinclude -mean's'for floating the impeller shaft in itsbearfings on a full. lmof a lubricant .which serves.l also as a seal againstthe passage of.-;the,

presser-Huid axially-along.the`shatt. :v:

Ano-ther object is-'toplovidea novelhal'lV bea-ref 1 ling assemblywherein the shaft, whenoperated under conditionsabove referred toiincluding both high speed and ,highpressure willabesuppo'rted upon and'entirely by., a; body .of liquidg lubricant maintained .as :a nlm?completely.:separating the `shaft and its bearing againstanyrdirectcontact,

owfotsuch lubricantg-throueh-the. respective portionspf thebearingmayfbe `regulated for maxmumveerlcyand;effectiveness,

Other .objects will become creadilylapparent to those skilled intheart..

While the instant disclosure constitutes ernyb cdimentof thebestmeansjlhaveythus fardef 1 vised for reducing theinvention,toppractice-it VA is to be understoodthatwithin;thescopegofthe invention as Aclaimed any.;.desredvariatmns ,and f,substitutions' maybe ymade instructural details In theaccompanying.dr.awi ngs, wherein like characters of reference designateglikepartsthroughout the severalviews-f-Y j IA v.:` .Figure 1 is-anaxiallongitudinalfsection,;partly in elevation, through a compressorequipped with. the invention. i

Figure 2 .isan enlarged*v detail enrialsection?` partly in elevation, ofa bearing assembly; spe..

vcifically thatgshown at' the-left of Figurev '1' Figure 3 is artransverse vsectiontakenion the. Figure eisen@ atransversesctictakeifo.-

.Figure .5 is an enlarged fragmentary. asiaijse'ci y v pressureend/Withgjangoutlet or4 exhaust- The'V successiveystages are'Qdened b'ythe-respective impellers I0, Il and I2 which discharge radially shaftfrom the zone of higher pressure to the zone of lower pressure asdefined by the division Wall 2U.

The same relationship of parts and the operation as described inconnection with the iirst A'stage bearing holds true with respect to thesucceeding stages, so that it is unnecessary to repeat the description.The important factorin all is into their respective volutes cr difiusorsI3, Ih'

and I5. The impellers are fixed to theaxially extending pump shaft I6for rotation therewith the shaft passing entirelythroughgthes-pprnp.;in-.r bearing bushings II, I8 and I YS4 mountedaxially in the fixed Walls 20, 2l and 2'2Jre'spectively which thatthespeed of rotation of the shaft I6 is suiciently'highftor draw thefzoilinto v,affull'-lrn upon Which'ithefshaft and its'zprojectediload isentirely supported, with no direct contact between shaft and bearing.The shaft is, in effect, floated upon kvarbodyuof oil which flows slowlyandccntinuously l5* the oil bodyl completely filling the entireaxiallyi-of the shaft during its service rotation,

' clearance space between shaft and bearing over divide the stages intheconventional mannerfof such pumps. The inner end of the inlet conduit 8fL openscommunication with thef, eye of; the

first stageimpelle'r: i' I Uf and I the dischargevr from'V the returnpassageffron thefi'rstvolute" I 3: opens: to the.'v eyl'of th-succeeding,or second.: sta'gefim'- pelle'r H and'i so son" throughout; th'ellongitudinal extent" o'ffthe pumpe the final sta'ge' discharge.Vbeing'lto the.,outlet/conduit 9'; Ateach end ot the v pump` casingthe-fsh'aft I5. extends through .the

, endv YWall,y beings4 journall'ed ins-.end bearings 23i'fLubrica'ntfgis'supplied tothe` inner bearingsill,

IS-'andl-ISflthrough supply conduits 25, 26 andzZfIf respectively,wh-iclrare passed through the'y casingl and: the volutestandiwhich`discharge int'oarmular` lubricant'i reservoirV grooves '28'.'providedinvthe,

shaft- |52' Each `groove is located near'thefhigh. pressure end of itsadjacent bearing. A Y

'As'y ther-pump fluid. pressure in each stage'I is higher'v thanl that?"in` the" immediately. preceding'. l' stage a; corresponding variationfin fpressure: is'.- require'd. in'r the -'individual :o ilcircu'latingfsysteinstrates that a definite I a'ridappreciable clearanceexists-between-tlieimpelleii shafti I6?. and l each ofshownfindetailiinfeii'igure 5i lThisA clearance;

shouldi approximate? `one'orf two i tlfious'andthsA of. i' an. inchgwhich:-r is appifeciabl-y:V larger than thee rniriir'nu'nirclearax'i'ce'f'requireement` 4of] one'h'alf." ythous'an'dthl; inchJwhich 1 machine y design tech noiogyteaches-.isfessenaarif#fuitninrlubrie:mm1l is' tot be'expeetedt`assumigftheiapprbpriateuubricant is used; Oil yof the-properviscsitnlsee Figure 5,- isA s'uppliedtotlie bearing'y I'unden v'apressure which isfonly slightly greater than'- the pump iiuid;pressurevl existing oir the f high: pre's-` y reservoir" groove- 282'isdisposed as close to f the high pressure end o f thebrngiasis-pr-aczticfable,vv andduey to-thefrelativelylsliglitf pressure.differential.' at ft'his'y endsvery little oil' will be"` forced fromthe bearing. Asth'e pumpuidl pressurin thev space'lat thellowlpressureeridof thebearn ing"betiineexi=` the Iwan* znfand: the lback @finiefini* peller- I0 is less than that existing adjacent-the eyeto'f: the.-se'condl stage impeller t I; and `less :than

tha-hydrostatic pressure :ori@the'oil'fsuppliedl the bearinggit isi.obvious L that'-r tlre'i .greater f prtt discharge into the space 32,completely 'llngtlie clearance l1spadei;betWee'nth' shaft'i and? bearingand presentingv a body ofi-liquidii'ivhichj-rendersllth'efentirelengthofthe bearing and thus sealing Ithe shaftagainstleakage of pump fluid from higherpressure zones to lower.

The outside sealsiat' thegendsoffthe'pump casin'g,:.wherefthe`sliaft'aextends through; the casing ends'e.is'ijaccomplished;l at. the"bearing' assemblies A 23:andiZlswhich:are'fsubstantially identical. iThe I assembly 23ris -i^1lustratediinidetail invr Figures l:

anEtiZ 'iandiitstdescriptiomwill suffice :fon both.-

' 'I'hezoikiseat principleI-is` the'. same as: that fortheinnerzbear-ings', .oi'li being-suppliedv through a.

support.r'neiriber` '3d-carried by the'adjacent end Wallzof-:theipximpcasing;.and.under a' hydrostatic pressure which is slightly greater thanthe pump fluidipre'ssure'; on;.the innerl facer of .I the`d end Walladiacenti tired eye oflthetfiirst *stage impeller AI D.

' The membrrf 3l ;isf internally threaded.' and recelves at its lextremeinnerzend'a, bearing 'bushing 3 'threadedth'ereinto and :of but smallIaxial extent; this#bushingitheingaoflthe same :internal di- Aazpcinthspaced faxialyifoutward beyond: the: outer end'. offth'ebushingf35 the ishaftf I 'G'.is formed :with

aislightly tapered reduced portionlwhichvcothreaded engagement whenthebushing 31 'is ap-` prpiiately rotatedi. itl/mayH be: axially'advanced cre'retractedwithrespect to the' member 34to .vary ther4radialI clearance existing1`l` between the taperedbushingandfthetaperedv portion' -of the sham-4v HandleverZ-rnean'i 38 are provided.loni the; tapered thus-hing @311' as'la'imeans for'veffecti'ng its'-adjustment';"and= lthr'eadedfvonto thel 'outer end of f :thezibu'shingisanfol collector` A3'!) drained by an' oilifreturn'fline f M means-foff whi'chf'the-foil thxugh system; individual ito the bearing fand`includin'glthe'supplydine andi `pump means; not

bearing is prevented bylmeansiof afconventional sturiingirbox glane-411'inf'tn'readed Vengagement Witlf thefzouter'jendof th`fm'en'iber34` andlbearvoir groovesl 28 ofthe inner bearings?and*com-A munie-ating:with-tue low peint l @15emechamber eol'vlectftfr'.L lI4-"-which; is*removable for impossibieztue: leakage: 'offfiiurp-uidfaioneilth zspumpedthrough the feed une as interne raser-1 Voir chambery 43 at a pressure`only slightly higher than that which exists at'the inner end ofthebushing 35.,.This keeps Ythe chamber fullofoil and maintainsa perfectsealwhich prevents :the egress of pump iluid. outwardly along the shaft.At. the Sametime some oil isforcedxoutthrough thesmall bushing. 35 into,the pump. inlet ad` `jacent the rst impeller .where;.it mayfbe removedwith some pump Ifluidandseparated1out yfor `further use or maybeVentrained with `the pump dfluid and be. disposed of,.ingsomeother way.VThe major body of oiliiows axially outv ward along the .shaft completelyfilling the clearance space and is receivedsinv the collector 30 fromWhichit is drained for recirculation,. as Ydes scribed." The vshaft is,`ofcourse,v rotatedat ,a

speed suiiicient to maintainfull lm supportof the shaftin thejbushings.i `In a `compressorvl of thetype herein disclosed itis vrdiiiiculttoprevent end movement of. the imf 3f peller shaftresulting,v fromthermal expansion, vibrationand strains inv various parts. ofthefapparatus. It is essential to the propervfunctioning of thesealthatitheclearance, between-the shaft and bushings must be maintainedsubstantially constant, and it would, therefore, seem on rstconsideration impractical to employ a conical bearing, and thiswould beso if it VWerenot for the .fact that in this invention the taper is madeso gradual that the greatest possible end motion of the shaft will notchangerthesealclearance more Ythan can be tolerated. The angle of taperas shown inl Figures 1 and 2, is very greatly ex` aggerated crpurposesof clarity i ndescription.

In actual practice I find a taper of 1/frto ,V2 degreebetween'surfaceand, axis` to be most satisfactory.-Y

nomic balance. iS made possible 4betweenlfriction' loss and; lubricantA.pumping loss. i l

Ii a lubricant of 1,1 centipoise average isco's-ll ity, is used, andthat is aboutas limpid .asisfre'fk 1iabl e ,1.thel pumping loss forlreturningfthe lubrif A cantv back Vto vthe-high pressure Iside is equalto tuefrCtiQn-IQSS Within the Oil'lm dile, wrote:

um,v for v@i1-,seal .tranchesm diameter-,and inches long running 72.00R. P.- M. having apres# sure differential of 1200 pounds per-squareinchacre-is ituhenthe -flmfhicknes isf .09k ethf when. these troussesartisanal. 'their total isa minimum?, et this vhigh. Speed the' @salamecannot L be reduced milch below this' 1-0015 inch.

To reduce it to l/g inch is ypermissibleV fromD a machine design4stangzlpointt)out twice the loss Within Athe lubijicantlmduetorotation-.ol

the snatk ex-istlsat about .21;'00v pounds per square inchpressure dropper. axiallinearinch o bear'- ing seal for a 2l inch y'shaft turning7200 R. M.

y Higher speeds pointto greater,clearances- YIn arrivi-11e, at theproperties-ree ftaner the limits of accuracy forvthebushingshat clear-Aance-as AWell as the limits of shaft end play are precalculatedandthetaper is then made gradual enough to `insure that the clearancetolerance is not exceeded. y ,s

Selection of a the viscosity of the lubricant are,r inter-relatedvWithithe speed of the impeller shaft, so there ,i5 a wide selectionpossible.. -As a general V rule it 'be Stated that the product O f theViscosity in centipoises and ,speedY in R. P'.V dividedvbyi theprojected Abearing load in pounds per square inch should be greater thanBrin order to obtain full nlm lubrication.

In actual practice,y operatinga high speed lrnul` t.

tistage centrifugal gas pump equipped with this invention at a shaftspeed yof v710014.. P'. lvl. oper-V ating under a pressure of 1,200poundsper square inch, using a 2" seal Sfvlongrwithraradial shaftbushingclearance of .00125 Ainch',only one quartI of light lubrieating'oilleakedpast the sealin 5l seconda This indicates thaththe quantity of oilpassed through the bearingclearance is smaller than might be expectedand demonstrates clearly that the power requiremen-tsor,returningvthelubricant to the high pressureside, at high speeds such as 3,000 to10,000 R. PQM.-ancl'high-- er, Where the pressure is several hundredorseveral thousand poundsL- compares most'ffav'orably with the powerloss incurred when operating vsuch machines at high speeds'y'vithnoshaft-` bushing 4clearancefor-with only anI inntesimal clearance, andproves the' ypracticability "and economicY advantage of lthe invention;Y Anjecolubricant proper ;viscosity, Y' bearing clearance, andnlengthof'bearing are all inlportant factors. The loaden, the bearing` and vgreater viscosity.'

Iclaim:f v .1 l. Inman, apparatus having Izones wherein dif? eten? fluidpressures :exist "partition fines-ns separating sama'alshaft extendingthrough' said partiti@ mgas iet@ thermes arid/rotatable at @Speed :above3000 .RffPf M- to acvmplsh the] function ofthe apparatus, fa bearing forsaid Shaft, 111th@ pefiiiioemeans. Said Sheitan@ bearing having a--radialcIearanCe *therebetween- When theV 'shaft is rotatedat litsfunctionals'peed, andlmleans maintaining the clearancespacecorm lGreater pressuregradients pointto lubricant'fstof v pletely filled WithaAb odyfof lubricant'undery, f

pressure notless `than thatv existing in the zor'ie'vV having.: the.higfheffprssuef 2. in an apparatus having vZonesy'vherein dif-' ferentyiiuid pressures ,s exist andpartitinllneans separating san1e-, a.sha ftextending through the partition means and rotatable at va above 30003.to `accomplish the function `of'tl'le apparatus;shearing ,fer SaidShaft-in therein-e tion meansgsaid l shaftA vand bearing' havingmaradial clearance ofA .001 inchfor@greaterthere;l bet-Ween when I4theshaft is rotated at its funnel tional speed, V:means maintainingltheclearance" space completely ,Afllled with a bodycf liqu" bricantat apressurenotless thanthateslsting in the v"zone ofthe higher. fluidpressure, and said shaftWhenrotatedet 'its intended'ul speed lbeingvfloated upon and entirelyl supported bythe,bdyioflubricant.v f' ,L

r.In' an apparatus having 'zonesof fluid pressuresdiv'iddf by apartition, 'ash'a'ft bearing in thegpartit'ion, a shaft rotatablein saidfilm" lubrication "atA a .shaft lspeevdfof three beariri'g'and`extending through the partition,

saidshaft 'and bearing having a radial clearance efjmorejthanjlccl men'wnerebytcpeniiit full" thousand RQPIM. and higher, and'rneanssupplying,a liquidj lubricant 'to said' bearing ataf pressure greaterthan thatexisting in thez'one ofhigher fluidrvpressure, whereby to Sealtheshaft,`

t l be varied. j

l 431m an apparatus having a shaft, a bearing therefor, and a liquidlubricant- 's't'i'pplied thereto in a'circulating system,- 'said shaftv'and bearing having a radial clearance vofv'not less than .001

inch, therefbeinga-'value 'of'I ZAN/P'- greater than 3,

where Z represents 'thelubricant viscosity, N the R; P.' M. of theshaft,and P; thcload on the bearing,and the intra-'ninifrictionfloss'of thelubri cant being balanced by'the'power loss in circulatingth'elubricant#- ofthe apparatus, Vthere biriga'radial clearance of notless-than lo'li'nchf'between said shaft and bearing over theentirexlength of thebear* ing, and-a liquid lubricating' mediumcontinuously supplied-to the bearing in excess of bearing requirementsduringV functional speed rota-i tion of the shaftwvhereby to maintainfull 4iilm lubricationof the shaftand-maintain the clearance space'completely filled 'with the lubricant, and thelubricant beingymaintained under a pressurehigher than that existing inthe zone havingthehigher fluid pressure, the clearance, lubricant viscosity,bearinglengthand shaft speed being sodefined as to approach av balanceof power losses, Anamely,fintrafilm friction and volumetric leakage.'

6. In adevi'ceof'the ycl'iaracter described having a partitionseparating zones" adapted to be maintained at diierent pressures, thecombination of a shaft passing through said partition, a bearing membersupportedfin said partition and of a size to embrace s'ai'dwshaft' witha fixed c radial spaced relation thereto, a bearing member plyinglubricant to bothof said bearing members from the spacebetweenthem,-andmeans` for adjusting said adjustable bearingjmember tovary the'radial spacingbetween said adjustable bear- Aing lmember andsaid shaft whereby lubricant ilow through both of said bearing membersmay 7'. In a device` of the character-described, in combination` with avpartition separating zones adapted to be maintained at differentpressures both 'oi rsaid bearings around' said shaft, and

means for varying thev radialv clearances between said' shaft and thebearing most remote from the high-pressure side of said partition.

8.'In a device ofthe character described, inA

omibinationrwith a partition separating` zones of different pressuresanda shaft passing through said partition,y saidA shafthaving' 'atapered zone `thereon-a pair of longitudinally spaced radial journalbearings ,surrounding Said shaft and carried by saidpar'tit'iointhe oneof Said be'arings most `remote from trie high pressure side' of saidparticin comprising a' bushing with the A 'anansa inner surface'taperedmto'substantially iit the tapered'zone on sald'shaft, means for4introducing a'. lubricant under 'pressure ,between saidl bearings tocause'lubrioant'to fiowthrough; both' of' Said bearings inoppo'sitedirections', andmeans for adjusting' f 'said bushing longitudinally.`Jwith r respoot to said shaft to vary the Iiow of'lubricantthroug'hzs'aid bearings. f c y f 9511i aidevic' oxathe charactercombination `with .a partit-ion 'separating Zones adapted tobemairitainedat different pressures and a' rotatable; shaft extending'therethrough, 'a pair oi'longitudinally spaced .parts embracing and"forming stricturesaround said shaft and carried. by' said' partition,said shaftand embracing parts havingsuicient radial clearance tapermit'full. fil-m lubrication at a vshaft'speed ofi3000 R. P. M. andhigher,'me'ans for introducing be'- tween the said embracing parts aiubricantunder pressure greater than? the' pressure o'n the highpressure siddof said partition to. cause. a.y ow of lubricant through'both of said embracing `parts around saidrshaft, Vand means vfor-`varying the radial clearancefbetwe'ensaid-"shaft and one' fsaidembracingipartar fr i 10.1111 a, device of the character described,in combination" with apartition separating zones adapted to be"maintainedatdieient pressures' and a rotatable shaft' extendingthe'rethrough,l a pair of longitudinally spaced parts embracing said'shaft and carried by said partition, one' of said 'embracing parts'providing a stricture and the other' a journal bearing, the' latter'being most remote' fromv 'the high pressure' side of the parti` means4for introducing between said embracing parts a, lubricant under'pressure greater than the pressure on the' high pressure side of saidparti tion' tocause'a flow' of' lubricant through both of saidembracing" parts around said shaft', and means for varying the radialclearancebetween said shaft 'andthe ern-bracingr` part most' remotefrom' the' high pressure'side of said partition.

11.'.In a device' "oi tlie character described,`in combination 'wi'thapar-titi-on separating zones adapted to be maintainedat differentpressures and a 'rotatable shaft eiitending therethrough, a pair' oflongitudinally spaced parts embracing and forming StriCturesarOu'Iidsaid shaft and carried by said partition, said 's'liaft' and embracingparts having sufii'cientradial'clearance to permit'full lm lubricationat. a shaft speed-of 3000 Ri. P. M.

and higher, means fo'rintroducing between said embracing parts''a'.flille-ricant under pressure greater than the pressure rvon the highpressure side of' said'partiti'orr'to cause a fic-W of iubricant throughboth draai'd embracing parts 'around said shaft, andv n'rearisfr foradjusting' lthe radial clearance between said shaft and the embracingpart most remotefroiiithehigh pressure side of partition tosuoh-adeg'ree vthat said last mentioned embracing' p'art Will act as aradial bearing for'said shaft `Whilestill permitting a flow of`lubrisant-through said embracing part to provide a complete oil filmbetween; said 'embracing part and said shaft. t A n f i2, v,In a device.ofgthech'aracter described, in combination' witha partition `separatingzones a'daptedito be" maintained at diiTerent-pressures and a rotatableshaft'extending therethrough, -a journal-bearing .surrounding said shaftand carriedby'said partition, additional means surroundin'g Said.' shaftiii spaced' relation with respect t0 described, in;

said journal bearing and of a size kto provide an annular clearancebetween said member and said shaft, said shaft andthe bearing andadditional means surrounding the same having sufficient radial clearanceto permit fullI lm lubrication at a shaft speed of 3000 R. P. M. andhigher, means for introducing between said bearing and saidv member alubricant under pressure greater'than the pressure on the high pressureside of said partition to cause a flow of lubricant through said bearingand said member around said shaft, and means for varying the radialclearance be-r tween said shaft and said member. i

13. In a device of the character described, in combination with apartition separating Zones adapted to be maintained at differentpressures and a rotatable shaft extending therethrough, a part embracingand forming a stricture around said shaft and carried by said partition,means providing a chamber in communication with the end of said iirstembracing part which is most remote from the high pressure Zoneand'including a second embracing part spaced from said first embracingpart and surrounding but not in contact with said shaft, said shaft andembracing parts having sufficient radial clearance topermit full filmlubrication at a shaft speed ofv 3000 chamber, and means for Varying theamount of clearance between said second embracing part and the shaft.

14. In a device ofthe character described, combination with a partitionseparating zones adapted to be maintained at different pressures and arotatable shaft extending therethrough, a partembracing and formingy astricture around said shaft and carried by said partition, means spacedfrom said embracing part and surrounding said shaft and spaced from saidshaft in allv directions, said shaft and the embracing part andsurrounding means' having sufficient radial clearance to permit `fulli'ilnrlubrication at a shaft speed of; 3000 R..P. M. and higher, meansfor introducing a lubricant under pressure greater than the pressure onthe high pressure side 0f said partition between said embracing part andthe'means spaced therefrom, and means for Varying the space between saidshaft and thesaid last mentioned means.-

15. ma. device of the character described, in

thereof which is vmost remote 'from the Zone of higher pressure andsurrounding said shaft out of actual Contact therewith for` limiting aow of fluid from the direction of said embracing -part along said shaft,said shaft and the embracing part and surrounding means havingsufficient radial clearance to permit full' lm lubrication at l a shaftspeed of 3000 RL P. M. and higher, means bracing part and the meansspaced therefrom and.- means for varying the'` resistance to flow oflubricant through said last mentioned means.

JUDsoN s. SWEARINGEN.

